Diodes Incorporated PI4IOE5V9522UEX

Overview

PI4IOE5V9522UEX from Diodes Incorporated (acquired Pericom Semiconductor) is a 4-bit I²C/SMBus GPIO expander with active-low interrupt and reset, 5V-tolerant I/Os, 2.3–5.5 V supply range, and MSOP-10 package. It serves as a low-power remote I/O interface for ACPI power switches, push buttons, LEDs, fans, and sensors in embedded control subsystems.

For engineers reviewing the PI4IOE5V9522UEX datasheet, PI4IOE5V9522UEX pinout, PI4IOE5V9522UEX application, or PI4IOE5V9522UEX equivalent, key selection criteria include I²C clock support up to 1 MHz, open-drain INT output timing (≤4 µs), standby current ≤1 µA at 5.5 V, and 5V-tolerant inputs enabling mixed-voltage system interfacing.

Technical Context

The PI4IOE5V9522UEX implements a register-mapped I²C slave interface with four dedicated I/O pins, configurable per-pin direction (input/output) via Configuration Register, and polarity inversion per input bit. Its interrupt logic triggers on state change of any configured input pin and clears upon reading the Input Port register.

It supports Standard (100 kHz), Fast (400 kHz), and Fast-Plus (1 MHz) I²C modes, includes noise filtering on SCL/SDA, and features power-on reset with VPOR = 1.16–1.41 V. The RESET pin provides synchronous hardware reset without cycling VCC, with minimum pulse width of 25 ns and recovery time <1 µs.

Key Specifications

Pinout & Package

Package: MSOP-10 (Mini Small Outline Package), 3.0 mm × 4.9 mm, 0.5 mm pitch, exposed pad optional, RoHS-compliant, Pb-free and Green (E suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C GPIO expander applications.

Compared with TCA6408A and PCA9534A, the PI4IOE5V9522UEX delivers superior noise immunity (50 ns spike suppression), faster I²C throughput (1 MHz), and hardware-accelerated input polarity handling-making it optimal for real-time industrial control and battery-constrained edge devices.

Availability

PI4IOE5V9522UEX is available at Aetrix Electronics and suitable for ACPI power management, industrial sensor interface, LED status indication, and fan speed control applications requiring stable component supply and long-term industrial lifecycle support.

Supply support for PI4IOE5V9522UEX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated acquired Pericom Semiconductor in 2017 and integrates its high-performance interface and timing solutions into a broad portfolio serving computing, industrial, and communications markets.

The PI4IOE5V9522UEX belongs to Diodes' I²C GPIO expander product line, designed specifically for space-constrained, low-power embedded systems needing reliable remote I/O expansion with hardware interrupt and reset capabilities.

FAQ

What is the minimum VCC required for reliable reset release?

The PI4IOE5V9522UEX releases internal reset when VCC rises above the power-on reset threshold VPOR, specified as 1.16 V (min) to 1.41 V (max). Below 1.16 V, the device remains held in reset regardless of RESET pin state. This ensures deterministic initialization during slow or noisy power ramps.

Can IO0–IO3 drive LEDs directly without external transistors?

Yes - each I/O can sink up to 10 mA at VOL = 0.7 V (VCC = 3.0 V) and source up to 8 mA at VOH = 2.5 V (VCC = 3.0 V). For common-cathode LED connections, configure the pin as output and drive low; for common-anode, drive high. External current-limiting resistors are mandatory per I/O.

How does the interrupt clear after being asserted?

The open-drain INT pin de-asserts only when the Input Port register is read by the I²C master - not merely upon state reversion. This ensures the host captures the exact input state that triggered the interrupt. If the input changes again before the register read, INT remains asserted.

Is the SDA pin truly bidirectional in hardware?

Yes - the SDA terminal contains an integrated open-drain buffer with internal weak pull-up, enabling true bidirectional data transfer per I²C specification. No external direction control is needed; the device automatically switches between driving low and releasing high based on I²C protocol timing and arbitration.